Comparison of Threshold Estimation Using Click and LS CE-Chirp Stimuli with Behavioral Thresholds in Adults with Noise Induced Hearing Loss.

AIMS

The present study was designed to compare the threshold estimation with Auditory brainstem responses (ABRs) using two stimuli, click and LS CE-Chirp and behavioral thresholds in men with noise induced hearing loss (NIHL).

MATERIALS AND METHODS

The ABR test was performed for 32 men, with a mean age of 36.06 years and moderate hearing loss in high frequencies. Threshold was considered as the lowest intensity at which wave V could be identified and reproduced in two repeated measurements. For data analysis, Wilcoxon test was used for comparing the thresholds obtained from the two stimuli and spearman's test assessed the relationship between behavioral thresholds and those recorded by two stimuli.

RESULTS

The mean wave V threshold for the LS CE-Chirp stimulus was significantly lower than that for the click stimulus (-value = 0.001). Also, there was a significant positive correlation between the threshold of two stimuli with the behavioral threshold of 1000 to 4000 Hz (-value = 0.001). However, the correlation of behavioral threshold with LS CE-Chirp was higher than the Click stimulus in the 500 to 3000 Hz.

CONCLUSIONS

The present study demonstrated that threshold estimation with LS CE-Chirp stimulus can be obtained with a higher correlation and smaller difference from behavioral threshold in mid and low frequencies. Therefore, LS CE-Chirp can be used as a valuable stimulus for more accurate threshold estimation in individuals with noise induced hearing loss who do not cooperate in conventional pure-tone audiometry and referred to otolaryngologists for forensic follow-ups related to compensation claims.